Fabrication and evaluation of pH-sensitive nanoparticulate in-situ gel for ocular inflammation

The present study was aimed to prepare and characterise pH-triggered in-situ gel based ophthalmic drug delivery system of non-steroidal anti-inflammatory drug (NSAID), Ketorolac tromethamine (KT).KT loaded nanocarriers were developed by ionotropic gelation technique using chitosan as a matrix forming polymer, cross-linked by an anionic crosslinker sodium tripolyphosphate (TPP).Benzalkonium chlorides at suitable concentration were used as a preservative.The formulations were sterilized by moist heat sterilization as per I.P.The prepared nanoparticles were converted into in-situ gel using Gallen gum.The prepared formulations were evaluated for clarity, pH measurement, gelling capacity and in-vitro diffusion study.Under rheological investigation both solution and gel were found to be in pseudo plastic behaviour.The selected formulations showed sustained release over a period of more than 12 hrs with increased resident time.All studies shown favourable results; thus, in-situ gelling system is a valuable alternative to counter precorneal loss a major drawback in the ophthalmic preparation.1.